Algebra with powers.

Question

0

634

1

+1090

If 3^x+2 = 7, what is the value of 3^x+4?

A. 63 B. 21 C. 35 D. 81 E. NOT

This is the last problem from my math UIL test that I am unsure how to calculate.

+23252

+10

Best Answer

I'm assuming that the problem is 3^(x + 2) =7

Since 3^(x+ 2) = 3^x · 3^2

Then, 3^(x + 4) = 3^x · 3^4 which is (3^x · 3^2) · 3^2,

Thus, 3^(x + 4) is 9 times bigger than 3^(x+ 2) and 9 x 7 = 63

geno3141 Nov 8, 2014

geno3141 · Answer 1 · 2014-11-08T03:52:14

I'm assuming that the problem is 3^(x + 2) =7

Since 3^(x+ 2) = 3^x · 3^2

Then, 3^(x + 4) = 3^x · 3^4 which is (3^x · 3^2) · 3^2,

Thus, 3^(x + 4) is 9 times bigger than 3^(x+ 2) and 9 x 7 = 63